1. Field of the Invention
The present invention relates to a rupturable pressure relief member, and more particularly, to a rupturable pressure relief member which is resistant to vibration and thermal stresses.
2. Description of the Prior Art
A variety of pressure relief devices of the rupturable type have been developed and used heretofore. One form of rupturable pressure relief member commonly utilized for protecting pressure vessels and other systems containing fluids under pressure is the rupture disk. Rupture disks are substantially circular in shape and are supported between a pair of flanges or holders which are in turn connected to a relief connection of a pressure vessel or system. When the pressure within the vessel or system exceeds the design rupture pressure of the rupture disk, rupture occurs causing fluid pressure to be relieved. A great number of rupture disk designs have been developed and used heretofore including single part and composite part disks, prebulged and flat disks, and disks which include one or more parts having lines of weakness created therein by scores, slots, perforations, slits and the like formed on or in a surface thereof. Examples of rupturable pressure relief disks which include lines of weakness formed by scores are disclosed in U.S. Pat. Nos. 3,463,351; 3,484,817; and 4,122,595.
Another form of rupturable pressure relief member utilized heretofore is a burst panel (also called an explosion vent) which provides relief to explosion pressures before structural damage to equipment results. Examples of such burst panels are disclosed in U.S. Pat. Nos. 4,067,154 and 4,662,126. The burst panel disclosed in U.S. Pat. No. 4,662,126 is comprised of two frangible panels disposed in spaced face-to-face relationship with a core of expanded polyurethane foam therebetween which functions to dampen vibrations transmitted to the burst panel. Lines of weakness are formed in the two frangible panels by a plurality of elongated slots formed therein.
While the above-described rupturable pressure relief disks and burst panels are effective in applications where some small amount of vibration is transmitted thereto, they are generally ineffective in applications wherein appreciable vibration is encountered. That is, in applications involving appreciable vibration, premature failure of the disks or panels often results because of the vibration stresses transmitted thereto and exerted thereon without the pressure at which the disks or panels are designed to rupture ever being reached. An example of an application involving such vibration and also involving high thermal stresses in which the above-described prior art rupturable pressure relief devices are inadequate or ineffective is the overpressure protection of supercharged engines, e.g., race car engines. In such engines, the supercharging, i.e., the compressing and concentrating of fuels such as alcohol and air often result in explosions which destroy parts of the supercharger and/or engine and endanger lives.
By the present invention, an improved vibration resistant rupturable pressure relief member for providing overpressure protection to structures which are subject to high vibration and internal fluid pressure and temperature increases, such as supercharged engines, is provided.